For anyone unfamiliar with Xiu Xiu, "Apistat Commander" would be the song I'd recommend starting with when checking out this band. It's easily the most accessible thing they've recorded to date, but with that said, there's really not a whole lot about Xiu Xiu's music that screams "accessible," so approach with caution.
The song starts out innocently enough, with singer Jamie Stewart's barely audible moan and minimal synth backing, before ripping into a "cathartic attack mode" that sounds something like Nine Inch Nails raping the Cure. The song's best moment comes when Stewart screams, "oh, this relief/it's the oddest thing/ohmygod/ohmygod/ohmygod."
This is Buffalo Tom's best single, off their last 90s studio album Sleepy Eyed(Big Red Letter Day was a better album). It opens with an unorthodox chord progression played on an alternate-tuned guitar that desperately wants to resolve but makes you wait for the cathartic chorus. The insistent nature of the chord progression in the verses is what hooked me and it still does just as much as the first time I heard it.